Mavproxy does no goes back to prompt

After opening up mavproxy.

There prompt doesn’t comes up?
Usually have this Stabilize>
When I tried to key in commands. Nothing happened.
Anyone knows what happened?

Waiting for heartbeat from /dev/ttyACM0
online system 2
STABILIZE> Mode STABILIZE
AP: ArduCopter V4.0.7 (0bb18a15)
AP: ChibiOS: d4fce84e
AP: fmuv3 002B0035 34395117 32393630
AP: RCOut: PWM:1-12
AP: Frame: HEXA
Flight battery 100 percent
Received 1044 parameters
Saved 1044 parameters to mav_2_1.parm

anyway although I can’t send the command on console, I still can send it on pymavlink. so far no problem with me.

What OS and MAVProxy version?

I assume is the latest version. Running on Armbian. Access through SSH

You may need to press “enter” a few times to get the prompt back.